Genuinely asking, roughly how old are you? I'm in my early-mid twenties and of the ~100 people I keep in touch with my age range from high school, there has been one child born (by accident if the rumors are true) and zero marriages. Of the dozen or so people I keep in regular contact with I've gathered that this is not for lack of trying, either. Obviously there is bias here as this is all anecdotal, but I'm very curious as to how unique this situation is.
That was the same for me in my mid-20s. By my mid 30s, vast majority are married with children. People are waiting a little longer than the last generation, but it's still happening as normal.
I'm close to your age than some of the other commenters, but I also find that marriage/child statistic unsurprising, not least given the events of the last two years, and the assumption of a vaguely affluent, coastal peer group.
Mid-20s is nothing, especially if your peer group is college educated. My wife and I married at 25 a bit over 20 years ago. Even at that time, we were the first of our friends group to marry. We had our first child right about the time I turned 30. We were only the 2nd of our peer group to have a child. Today, all of our friends from back then are married (a few divorced) with kids.
The trend has been only towards waiting longer in the 20+ years since we were ahead of the curve.
If you're from an affluent background - being married in your 20s is weird. If you're single in your 30s - you should be worried but it's too late. By then - most of your friends will likely marry.